Dissertations / Theses on the topic 'Fluorescenza X'
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TISATO, Flavia. "Study on Modern and Contemporary works of Art through non invasive integrated physical techniques." Doctoral thesis, Università degli studi di Ferrara, 2014. http://hdl.handle.net/11392/2388948.
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During my PhD I developed two parallel and complementary topics, concerning both works of art and materials. The first one, focused on non-invasive investigations on works of art (ancient and contemporary), was aimed to deepen conservative state, material composition, painting techniques and the early detection of any deterioration. This latter goal also guided the study of pictorial and restoration materials, mainly aimed at their characterization from the optical point of view.
Diagnostic activities made use of different methods of investigation. Among image techniques, photography and macrophotography in diffuse, specular and raking light, ultraviolet fluorescent, image spectroscopy, wide band infrared reflectography, digital and differential K-edge radiography. To get as much information as possible, to be properly integrated with other data, punctual diagnostic techniques, such as reflectance spectrophotometry, colorimetry and X Ray fluorescence, were also used.
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Marchesini, Stefano. "X ray fluorescence holography." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10012.
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Dans de nombreux cas la structure atomique des solides ne peut etre resolue par les techniques traditionnelles de la cristallographie. Cela peut etre le cas, par exemple, pour les etudes locales d'impuretes diluees, les interfaces enterrees et plus generalement les systemes non periodiques. En 1996 une nouvelle methode structurale, l'holographie x a resolution atomique est apparue. Elle a pour origine la technique d'imagerie holographique, inventee par gabor il y a 50 ans. Dans ce travail, nous presentons d'abord le principe et le cadre theorique de l'holographie par fluorescence, fondes sur le concept de source / detecteur interne. Puis nous decrivons les developpements techniques que nous avons progressivement obtenus, afin de transposer cette methode des rayons x de laboratoire vers la source synchrotron esrf ; ceci sous le double point vue du montage experimental et de l'analyse des donnees. Des resultats intermediaires interessants sont l'imagerie des configurations des lignes de kossel et des ondes stationnaires, a partir desquelles des informations structurales - parametre de reseau, symetrie et orientation cristallines - peuvent etre deduites. Puis l'hologramme et la reconstruction atomique de monocristaux modeles tels que coo(111) sont presentes, avec - pour la premiere fois, une resolution isotrope de 0,5 a et une qualite d'image qui n'avait pas ete obtenue jusqu'a present. Enfin, la premiere application de l'holographie par fluorescence aux films epitaxiques est donnee. Des differences significatives entre des films d'alliages fept chimiquement ordonne et desordonne ont ete obtenus, ouvrant la voie a l'etude de l'ordre a courte distance directionnel dans de tels systemes, au-dela des possibilites de la spectroscopie xafs. De nouvelles perspectives sont offertes en conclusion, concernant l'holographie atomique resolue en temps, ainsi que - sur la base d'une etude preliminaire d'holographie nucleaire - le potentiel de cette technique pour le magnetisme local et la selectivite en site.
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ORSILLI, JACOPO. "AR-XRF Techniques for the Analysis of Cultural Heritage layered samples." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2023. https://hdl.handle.net/10281/403656.
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L’analisi scientifica è da un po’ di tempo entrata nel mondo dei beni culturali, non sono più solo gli archeologi e gli storici dell’arte a occuparsi dello studio dei reperti archeologici e storici, ma anche gli scienziati sono entrati a gamba tesa portando le loro conoscenze al servizio di questa vasta gamma di materiali. Lo studio di reperti botanici e zoologici, le competenze chimiche e mineralogiche, lo studio di fenomeni fisici, ha permesso di porre e rispondere a nuove domande, colmando così lacune sulla storia dell’umanità. Reti commerciali, migrazioni, tecniche produttive, molte sono state le scoperte avvenute grazie anche all’intervento scientifico, oltre a fornire strumenti utili al restauro e alla conservazione dei reperti.
Nei miei tre anni di dottorato mi sono occupato dell’applicazione dell’analisi in Fluorescenza a Raggi X (XRF) per analizzare campioni metallici e ceramici. Questa tecnica ha il vantaggio di poter essere applicata in maniera non invasiva e non distruttiva su un reperto per ottenere informazioni sulla sua composizione elementare. In particolare, il nostro obiettivo è quello di ottenere informazioni sui diversi strati che compongono un campione. Spesso, infatti, i manufatti presentano una struttura stratificata causata dal passaggio degli anni o dalla natura stessa dell’oggetto, che presenza una serie di decorazioni superficiali. L’impiego di tecniche non invasive permetterebbe quindi di ottenere informazioni più dettagliate anche su campioni al momento inaccessibili, in quanto troppo fragili o troppo preziosi.
Lo studio si è quindi avvalso di tecniche a scansione angolare, per cui il segnale di fluorescenza caratteristica dipende sia dalla posizione dell’analita all’interno del campione, sia dalla struttura e composizione dello stesso, sia dalla geometria di analisi. Per valutare l’applicabilità delle tecniche sono stati analizzati tre casi diversi: campioni metallici preparati ad hoc in laboratorio, un campione ceramico, e un campione di lustro.
Per i primi due campioni è stata applicata l’XRF a Risoluzione Angolare (AR-XRF) per cui il campione è stato ruotato con uno step angolare inferiore a un grado, e misurato ad ogni step. Nel caso dei campioni metallici i profili misurati sono stati confrontati direttamente con i profili calcolati usando il metodo dei Parametri Fondamentali. Nel caso del campione ceramico invece, sono stati confrontati i rapporti dei profili, in quanto la geometria del campione era piuttosto complessa.
Nello studio sui campioni metallici, composti da una doratura depositata su una lamina di rame, è stato possibile calcolare lo spessore dello strato superficiale. Nel caso del campione di Majolica sono invece state studiate le varie decorazioni, valutando così anche diversi limiti della tecnica, in particolar modo nel caso in cui la composizione della decorazione sia simile alla composizione dello strato sottostante, o nel caso in cui avvengano processi di diffusione a lunghe distanze. In casi in cui invece lo spessore della decorazione era limitato e ben separato dallo strato sottostante, è stato possibile ottenere informazioni sua sulla composizione della decorazione che sul suo spessore.
Infine, lo studio delle ceramiche lustrate è stato effettuato presso la linea XRF del Sincrotrone di Elettra, impiegando tecniche di analisi in radenza. In questo caso stato possibile solo evidenziare come il nano-strato di nano-particelle di argento, caratteristico di questa tipologia di campioni, sia effettivamente distinguibile applicando queste tecniche, in quanto il profilo di fluorescenza di tale elemento è molto diverso dagli altri.
Rimangono comunque dei problemi, legati soprattutto all’analisi dati e all’allineamento che vanno ancora risolti, rendendo necessari ulteriori studi a riguardo.In the last decades scientific analysis has been deeply employed in the world of cultural heritage, thus, archaeologists and art historians are no more the sole front line workers of this field. Scientists, and science, have joined the team, giving new inputs and tools for the study of historical and archaeological samples, allowing to explore new paths and receive new answers, collecting information otherwise inaccessible on human history and culture. New discoveries have been made on the trade networks, migrations and on the technologies employed; besides, science also gave precious inputs on conservation and restoring procedures, allowing to better preserve fragile and sensitive artifacts. In my three years as a PhD student, I worked on the application of X-Ray Fluorescence (XRF) analysis to analyze ceramic and metal samples. XRF is a non-invasive technique that retrieves the elemental composition of a sample. In particular the aim of my PhD project is to obtain information on the layered structure of an unknown sample, distinguishing and characterizing the different layers. Indeed, artifacts usually concerning the field of Cultural Heritage present a layered structure; sometimes it is due to the presence of alteration layers, other times, instead, the objects are made of different layers from the principle, for example in the case of a glazed ceramic or of a painting. The possibility to get this information in a non-invasive way will give the possibility to analyze objects that are nowadays unattainable, because they cannot be sampled. My project has, thus, focused on the analysis of three kinds of samples employing angular dependent techniques (Angle Resolved-XRF, Grazing Emission-XRF}, Grazing Incidence-XRF}); indeed, the fluorescence signal of an analyte depends on its position inside the sample, on the sample composition and on the geometry of analysis. The chosen specimens allowed to verify the feasibility of this analytical method in an increasing complexity: a gilded laboratory-made sample, a ceramic Majolica sherd, and an Italian renaissance lustered fragment. The first two samples have been analyzed through AR-XRF where the measure is performed while tilting the sample, one spectrum is collected for each tilting angle. In the case of the gilded sample the measured profiles have been compared directly with the calculated profiles employing the Fundamental Parameters method. For the ceramic Majolica sample, instead, we studied the ratio of the profiles, as the sample surface is not flat. In the study of the metallic samples, made of gilded copper plate, we could infer the thickness of the top-layer. While in the case of the Majolica sample, we studied the different decorations, evaluating the limits of the technique, in particular in the case that the top-layer composition is similar to the underling layer, or in the case of a long-range diffusion. Instead, in the case of two well-separate layers we could retrieve information on both the composition and the thickness of the layer. Finally, the study of the lustered ceramic has been carried out at the XRF beamline of the Elettra Synchrotron of Trieste, employing grazing techniques. In this case we could only highlight and distinguish the presence of the silver nanoparticles in the luster nanolayer, which is the peculiar feature of this kind of artifacts. However, there are still many questions left, especially concerning the data analysis and the alignment of the sample, which requires more investigations.
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Sargenti, Azzurra <1986>. "Study of Magnesium Homeostasis and Intracellular Compartmentalization in Human Cells by Fluorescent Chemosensors and Synchrotron X-Ray Fluorescence." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7496/1/Sargenti_Azzurra_tesi.pdf.
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In this study, we investigated the analytical capabilities of DCHQ5, a new fluorescent chemosensor, belonging to the family of diaza-crown-hydroxyquinolines, for the quantitative assessment of total intracellular magnesium content, and its biological applications. We performed a comparative study of DCHQ5 and DCHQ1, the latter being the mother probe of the series, which showed preliminary encouraging results comparable to atomic absorption spectroscopy. We demonstrated that DCHQ5 is able to accurately quantify the total amount of Mg in a very “small” cellular population, by using a simple spectrofluorimetric assay. Furthermore, DCHQ5 demonstrated to be a versatile tool for different applications: its higher intracellular retentions allow to perform cytofluorimetric assays and two-photon confocal microscopy on whole and viable cells; its photochemical characteristic make it excitable in both UV and visible spectra, and the presence of different lifetimes allow to perform fluorescence life time imaging of intracellular Mg.
DCHQ5 was also exploited for studying the involvement of magnesium in the commitment of human adipose-derived mesenchymal stem cells (hASCs) with a mixture of hyaluronic, butyric and retinoic acids (HBR). We found that in normal magnesium availability, hASCs precommitment is associated by an increase of total magnesium content during time and by a block in the G2/M phase of the cell cycle. Moreover, our results demonstrated that magnesium deprivation triggers multilineage enrichments of HBR-induced preconditioning of hASCs.
The second part of this research was aimed at comparing single cells elemental analysis performed with synchrotron-based fluorescence and cell population analysis carry out by DCHQ5. We exploited innovative techniques of x-ray fluorescence microscopy by using a multimodal approach in order to achieve within the cells the spatial distribution of the concentration of magnesium and fundamental light elements for life. The combination of classical and innovative analytical techniques can shed new light in the comprehension of magnesium homeostasis.
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Sargenti, Azzurra <1986>. "Study of Magnesium Homeostasis and Intracellular Compartmentalization in Human Cells by Fluorescent Chemosensors and Synchrotron X-Ray Fluorescence." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7496/.
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In this study, we investigated the analytical capabilities of DCHQ5, a new fluorescent chemosensor, belonging to the family of diaza-crown-hydroxyquinolines, for the quantitative assessment of total intracellular magnesium content, and its biological applications. We performed a comparative study of DCHQ5 and DCHQ1, the latter being the mother probe of the series, which showed preliminary encouraging results comparable to atomic absorption spectroscopy. We demonstrated that DCHQ5 is able to accurately quantify the total amount of Mg in a very “small” cellular population, by using a simple spectrofluorimetric assay. Furthermore, DCHQ5 demonstrated to be a versatile tool for different applications: its higher intracellular retentions allow to perform cytofluorimetric assays and two-photon confocal microscopy on whole and viable cells; its photochemical characteristic make it excitable in both UV and visible spectra, and the presence of different lifetimes allow to perform fluorescence life time imaging of intracellular Mg.
DCHQ5 was also exploited for studying the involvement of magnesium in the commitment of human adipose-derived mesenchymal stem cells (hASCs) with a mixture of hyaluronic, butyric and retinoic acids (HBR). We found that in normal magnesium availability, hASCs precommitment is associated by an increase of total magnesium content during time and by a block in the G2/M phase of the cell cycle. Moreover, our results demonstrated that magnesium deprivation triggers multilineage enrichments of HBR-induced preconditioning of hASCs.
The second part of this research was aimed at comparing single cells elemental analysis performed with synchrotron-based fluorescence and cell population analysis carry out by DCHQ5. We exploited innovative techniques of x-ray fluorescence microscopy by using a multimodal approach in order to achieve within the cells the spatial distribution of the concentration of magnesium and fundamental light elements for life. The combination of classical and innovative analytical techniques can shed new light in the comprehension of magnesium homeostasis.
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Heiden, Thomas. "Clinical fluorescence cytometry : improvements to preparation methods and instrumentation /." Stockholm, 1999. http://diss.kib.ki.se/1999/91-628-3648-X/.
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An, Siwen. "X-ray Fluorescence Spectrometry for Environmental Applications." Licentiate thesis, Mittuniversitetet, Institutionen för elektronikkonstruktion, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39979.
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Heavy metal contamination in environmental applications is particularly important because of its potential impact on associated ecosystems and human health. At present, monitoring of heavy metals is usually done by taking and preparing samples for off-line laboratory measurements. X-ray fluorescence (XRF) analysis is a powerful and widely used tool for determining the elemental composition and concentration of chemical species in materials. This project is a feasibility study for the possibility of on-line XRF systems for continuousand direct analysis of industrial processes and environmental emissions. The feasibility of such measurements depends on the accuracy with which the concentration can be measured within a given response time. Therefore, this project is focused on investigating possible background suppression of the XRF spectrum. First, an XRF setup has been built, and its capability has been compared to a commercial scanning electron microscope with energy dispersive spectroscopy (SEM-EDS). The qualitative analysis and semi-quantitative analysis of heavy metal contamination in fly ash was performed and compared. Due to minimal sample preparation, the developed XRF system is suitable for in-situ measurements. A series of experiments was performed to optimize the signal-to-noise ratio of the spectra achieved from chromium contaminated liquid samples. The most significant factor turned out to be the primary X-ray source filter. Numerical simulation models have been developed in the Monte Carlo N-particle radiation transport code (MCNP), to calculate the X-ray fluorescence intensities and the detection limit for chromium in liquid samples. The experimental results agree with the results predicted by the simulation model, hence the model is used for optimization of the XRF system. Further, XRF mapping of chemical element distributions on a microscopic level has been obtained by using both X-ray scanning microscopy and full-field projection microscopy. The resultingdata from these microscopy measurements can guide further comprehensive environmental and industrial monitoring missions by providing additional spatial distribution information. In conclusion, the first research contribution presented in this thesis is the demonstration of the possibility to perform in-situ XRF measurements of chromium contamination in leachate with a limit of detection below the legal environmental limits. The second is the demonstration of XRF mapping on amicroscopy level, where a polycapillary X-ray optics setup achieves a similar intensity as a geometrically corresponding pinhole optics setup.Vid tidpunkten för framläggningen av avhandlingen var följande delarbeten opublicerade: delarbete 2 (inskickat), delarbete 3 (accepterat), delarbete 4 (accepterat).
At the time of the defence the following papers were unpublished: paper 2 (submitted), paper 3 (accepted), paper 4 (accepted).
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Ida, Hiroyuki. "X-ray fluorescence analysis with portable instruments." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144877.
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Liu, Ying. "Low Power Total Reflection X-Ray Fluorescence Spectrometry." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/192191.
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Abbott, Paul H. "Heuristically guided interpretation of X-ray fluorescence spectra." Thesis, University of Wolverhampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309784.
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Abdul, Wahid Fatmawati. "Characterising concrete using micro X-ray fluorescence (uXRF)." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/55139.
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Micro X-ray fluorescence (µXRF) is a relatively new technique that is able to perform elemental analyses at high resolution. However, very few studies have been carried out to apply this technique for cement and concrete research. This thesis aims to develop, optimise, and exploit µXRF as a technique for characterising concrete and for studying transport of aggressive species such as chloride and sulphate in cement-based materials. This is important because µXRF has several advantages over existing techniques and the ability to detect the presence of aggressive species, measure their amount and rate of penetration is a key aspect in characterising long-term durability of concrete structures. The effect of seven operating conditions of µXRF on its sensitivity to chloride and sulphate was first investigated to understand factors influencing accuracy and to determine optimum operating conditions. The results show that the signal-to-noise ratio (SNR) and limit of detection (LOD) for chloride and sulphur improves when the analysis is carried out at higher beam voltages, longer acquisition times, in vacuum chamber and using a 30 µm beam spot. The application of 25 µm aluminium filter improves chloride analysis, but this is not necessary for sulphur analysis. A dead time of 30 – 50% and an amplifier time constant of 12.8 µs is recommended to obtain an optimised set-up. At these conditions, a LOD of 0.007% wt. cement for chloride and 0.003% wt. cement for sulphur is achievable. The ability to separate cement paste regions from aggregate particles during µXRF analysis is important as it helps to reduce signal interference and allow measurements solely on cement paste or aggregate particles. A new approach for identifying cement paste regions in mortars and concretes has been developed. This method is based on exploiting the change in dead time when the beam samples cement paste or aggregate regions. The main advantage of this approach over conventional elemental mapping and image analysis is speed and ease of use. Calibration graphs for chloride and sulphate in cement-based materials have been developed to enable quantitative analysis. This is done by analysing samples containing known amounts of chloride (or sulphate) and examining the strength of the correlation between measured X-ray intensities and actual amounts. A strong linear correlation (R2 > 0.9) is observed for a range of samples with a different w/c ratio, binder type, curing age, and drying condition. This is also observed when samples were analysed in a wet state (as-is) in ambient environment. These findings provide evidence that the measured characteristic X-ray intensities from µXRF and the observed correlations can be used for quantitative analysis of unknown samples. Sample drying and moisture state has a major effect on the measured X-ray intensities. This was investigated to establish an appropriate preparation method for µXRF analysis of mass transport processes in cement-based materials. Rapid oven drying at 50°C distorts the measured chloride profiles. However, freeze-drying was able to preserve chloride profiles much better, producing identical chloride penetration depths to that measured before drying. Analysis on a flat ground surface provides more representative results than that on rough fractured surfaces. Finally, quantitative analysis of chloride and sulphate was demonstrated by combining the proposed dead time approach and calibration graphs. Results from µXRF are comparable to those from wet chemistry analysis (titration). The study also provides evidence that µXRF has sufficient sensitivity to detect changes in transport properties of samples with different binder types, water/binder ratio and drying conditions.
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Carter, James Andrew. "Lunar surface composition from X-ray fluorescence spectroscopy." Thesis, Aberystwyth University, 2013. http://hdl.handle.net/2160/bda827d4-7dc7-46d5-b92a-ff18dc37d7a0.
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What is the composition of the surface of the Moon? This investigation aims to map the abundances of some of the main rock-forming elements over the surface of the Moon. Accurately determining the magnesium, aluminium and silicon abundances would have great advantages when performing geological and geochemical studies of the Earth-Moon system, helping to answer questions about its formation and evolution. This thesis uses data from the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument on Chandryanaan-1, a high quality instrument that nevertheless flew in one of the lowest solar minima on record. Modelling software is described and written to predict the performance of an orbiting X-ray spectrometer (XRS) under different conditions, a vital task for premission planning and post-mission analysis. Surface factors, such as compositional modification by crater rays and the enhancement of X-ray returns by volatile sodium, are modelled to assess their effects on XRS signals. The C1XS data is processed using a data pipeline, and inspected and analysed. After some post-pipeline processing maps are produced, first elemental line intensity ratio maps, and then absolute elemental abundance maps. These are produced for the southern nearside lunar highlands, and are then compared to previous datasets and ground truth.
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GALLET, JEAN-JACQUES. "Dichroisme circulaire magnetique en fluorescence x haute resolution." Paris 11, 1997. http://www.theses.fr/1997PA112426.
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Ce travail est une exploration des informations que l'on peut obtenir par l'analyse a haute resolution de la fluorescence x resultant d'une excitation produite par du rayonnement synchrotron (lure, esrf). Apres des rappels sur l'interaction photons x-matiere, les possibilites attendues theoriquement lorsque la fluorescence est induite par des photons polarises ou en resonance sont discutees. Les evolutions des spectrometres pour tirer parti des sources synchrotron modernes et les dispositifs d'aimantation pour les mesures de dichroisme circulaire magnetique (mcd) sont decrits. Les premiers resultats de mcd dans l'emission fe 3d 2p sont presentes et compares a des experiences ulterieures. Des resultats theoriques leur sont confrontes pour comprendre comment le mcd est lie a la polarisation en spin des etats de valence des elements magnetiques. La selectivite chimique du mcd est alors utilisee pour sonder, pour la premiere fois, la structure electronique magnetique du rh dans co75rh25. L'effet de l'hybridation sur le magnetisme est etudie par substitution de co (rh) par ni (pd). Enfin, des experiences de diffusion x inelastique resonante (rixs) sur fef3 au seuil fe 2p et du gadolinium au seuil gd 4d sont presentees. Elles illustrent les possibilites nouvelles offertes par le rixs : l'etat intermediaire atteint a partir de l'etat fondamental a la suite de l'absorption du photon est controle et la desexcitation de cet etat se fait soit vers l'etat fondamental, soit vers un etat excite, soit par un effet raman resonant. On accede ainsi a des configurations qu'il n'est pas possible de sonder hors resonance, ce qui est d'une importance cruciale pour etudier les transferts de charge et les effets d'hybridation dans les systemes a electrons fortement correles. Le rixs permet aussi de separer des voies d'excitation differentes : nous avons pu distinguer les contributions dipolaire et quadrupolaire au spectre d'absorption sm 2p en etudiant le spectre d'emission 3d 2p.
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Jbeli, Haïsam. "Analyse élémentaire par fluorescence X en dispersion d'énergie." Clermont-Ferrand 2, 1988. http://www.theses.fr/1988CLF21138.
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Principe, caractéristiques des spectres d'excitation. Effets de matrice, notion d'énergie équivalente, méthode de correction des effets interéléments. Résultats d'analyse. Caractérisation de couches minces
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JIBAOUI, HUSSEIN. "Microscopie x par reflexion totale et par fluorescence." Reims, 1999. http://www.theses.fr/1999REIMS032.
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Les progres des sciences fondamentales aussi bien que ceux de la technologie passe par le developpement de nouvelles methodes d'investigation de la matiere. Parmi la proliferation de techniques existantes celles mettant en uvre des rayons x incidents et detectes (diffraction x, fluorescence x, etc) ont pour but de caracteriser le volume des materiaux et seule les mesures de reflectivite x a incidence rasante (au voisinage de la reflexion totale) donnent acces a la structure des premieres couches superficielles, mais ces mesures de reflectivite integrent les informations laterales sur des surfaces superieures au mm 2. Ce memoire a pour but de montrer, pour la premiere fois a notre connaissance, qu'il est possible d'utiliser les rayons x a incidence rasante pour former des images de surfaces et d'interfaces avec une resolution laterale de l'ordre du micron, une sensibilite aux denivellations topographiques de l'ordre du nanometre et une localisation d'ecarts angulaires a la planeite de l'ordre du microradian. Les surfaces imagees sont de l'ordre du millimetre carre et les images sont acquises en quelques secondes a l'aide d'un prototype base sur les modifications d'un microscope electronique a balayage. Ainsi donc le memoire aborde successivement les principes physiques de base, l'evaluation des performances et de nombreux resultats experimentaux etayant cette evaluation. La meme demarche est appliquee a l'etude des interfaces solide/solide et des images de topographie des interfaces ont ete obtenues grace au pouvoir penetrant des rayons x. Cette approche de la visualisation directe des interfaces constitue, a notre sens, une nouvelle voie d'investigation dans un domaine ou les techniques concurrentes s'averent impuissantes. A partir du meme instrument, nous avons enfin demontre qu'il est aussi possible de mettre en uvre une autre microscopie : la microscopie x a fluorescence a faible incidence. La faisabilite de la methode a ete illustree par des images chimiques et topographiques. Les perfectionnement a apporter a la technique aussi bien que les perspectives qu'elle ouvre sont aussi brievement evoquees.
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Ruch, Claude. "Analyse d'elements traces par fluorescence x : nouveaux developpements." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13107.
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L'analyse d'elements presents a l'etat de trace (concentration inferieures au mu nongg) connait un developpement important dans l'etude de l'environnement, en medecine et en biologie. Tous ces domaines requierent un nombre d'analyses eleve d'echantillons pour conduire a des resultats significatifs. Le nombre d'elements qui gagnent en importance ne cesse de croitre. La spectrometrie a dispersion d'energie repond parfaitement a ces besoins par une analyse multielementaire rapide, sans preparation chimique et d'une tres grande fiabilite. Une automatisation aisee permet des mesures de routine vingt quatre heures sur vingt quatre de quelques dizaines d'elements dans le domaine du n nongg
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Ruch, Claude. "Analyse d'éléments tracés par fluorescence X nouveaux développements /." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37600902j.
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Jbeli, Haïsam. "Analyse élémentaire par fluorescence X en dispersion d'énergie." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376145227.
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BOLORTUYA, Damdinsuren. "Portable X-Ray Fluorescence Spectrometer with High Sensitivity." Kyoto University, 2019. http://hdl.handle.net/2433/242503.
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Mukhtar, Sarfraz. "Fundamental analytical studies into total reflectance X-ray fluorescence." Thesis, University of Greenwich, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280438.
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Duren, Leigh C. "X-Ray Fluorescence Measurements Of Molten Aluminum Elemental Composition." Digital WPI, 2008. https://digitalcommons.wpi.edu/etd-theses/43.
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The aluminum industry is in need of high-speed in-situ elemental identification technology for molten metals. wTe Corporation of Bedford, MA was granted funds to research this technology for aluminum through the Advanced Technology Program (ATP) of the National Institute of Standards and Technology (NIST). As a secondary metal scrap processor, wTe Corporation is interested in increasing the value of scrap and better identification technology is one way of doing this. With better identification technology, foundries and smelters will be more confident in the melt chemistry and more apt to use secondary aluminum which decreases the energy required for processing by approximately 85%. wTe Corporation is exploring two avenues for in-situ molten metal identification: Laser Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF). The objectives of this work were to contribute to developing XRF technology for in-situ identification of molten metal by establishing a method of data instrumentation and analysis for XRF to determine aluminum melt composition, investigate the major alloying elements in the Al380 alloy series and determine the relationship between intensity and concentration, and to determine the effect of temperature on XRF Spectra. The XRF instrumentation development and the technical challenges associated with high temperature measurements are presented. The relationship between intensity and concentration is presented for three alloys within the 380 alloy series, and lastly it is observed that there are significant differences between liquid and solid spectra and that a calibration curve for liquid data is necessary. Several hypotheses are given as to why this difference between liquid and solid state spectra may occur.
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Huré, Laurent. "Etude de l'application de la fluorescence induite par flash de rayonnement X et de la radiographie "éclair" au diagnostic et à la caractérisation de milieux mono- et diphasiques en écoulement." Orléans, 2000. http://www.theses.fr/2000ORLE2043.
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Les écoulements mono- et diphasiques, rencontrés dans les technologies moteur et propulseur font à l'heure actuelle l'objet de nombreuses recherches. Un enjeu majeur réside dans la possibilité de caractériser les régions des écoulements situées en sortie d'injecteur. Pour ces régions, la radiographie "éclair" et l'imagerie de fluorescence induite par flash X offrent deux méthodes de diagnostics complémentaires aux techniques optiques traditionnelles. Ces diagnostics X se révèlent particulièrement prometteurs lorsque l'objet étudié est masqué par de fortes émissions lumineuses. Dans ce travail, une source flasch X développée au GREMI et émettant des impulsions de 20 ns a été optimisée. Les doses, mesurées à sa fenêtre de sortie, atteignent le roentgen par tir. Les photons X, dont la majorité a une énergie inférieure à la dizaine de kiloélectronvolts, proviennent essentiellement des raies d'émission caractéristiques du matériau constituant l'anode (tungstène et fer dans cette étude). Des radiographies "éclair" ont été réalisées sur des jets de gaz et des sprays se détendant dans l'air ambiant à pression atmosphérique. Dans le cas de jets d'argon et d'eau présentant une géométrie cylindrique, un algorithme de calcul a été développé. Il permet de mesurer des densités d'espèces pour des coupes transverses dans l'écoulement. La fluorescence induite par flash X (FIX), provient de l'excitation par les photons X des espèces du jet. Dans ce travail, cette fluorescence, caractéristique des espèces excitées, a été enregistrée en utilisant des détecteurs CCD intensifiés. L'imagerie filtrée en longueurs d'onde permet de visualiser leur distribution spatiale et de mettre en évidence des zones de mélange dans les jets. L'imagerie de fluorescence induite par flash (IdeFX) et la radiographie "éclair" permettent une résolution temporelle de quelques dizaines de nanosecondes adaptée à la caractérisation de phénomènes rapides.
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Hase, Thomas Paul Anselm. "X-ray scattering from magnetic metallic multilayers." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4652/.
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Study of structure and interface morphology of magnetic thin films is crucial in obtaining a better understanding of the coupling mechanisms in such systems. In this thesis various x-ray scattering techniques are applied to a series of Co/Cr trilayers, Cu/Co multilayers and spin valve structures. It is demonstrated that modifications to the distorted wave Born approximation allow the modelling of grazing incidence diffuse scatter originating from graded systems such as Co/Cr. Grazing incidence scattering techniques are also employed to investigate the out of plane correlations of lateral roughness in Cu/Co multilayers, as well as in miscible trilayer structures. The use of soft x-rays in the investigation of 3d transition metal multilayers is also presented. Such experiments are sensitive to the component of magnetisation aligned with the direction of the incident beam. In a series of magnetisation experiments, the dependence of the x-ray scatter sensitive to this component of magnetisation are analysed. For the first time evidenced is found for correlated magnetic roughness, which has lateral correlation lengths far greater than the structural roughness length scales. This magnetic roughness is measured in detail, and the correlation length is found to vary with applied field direction. Grazing incidence x-ray fluorescence is applied to two spin valve structures. These experiments provide a direct measure of buried layer thicknesses which is not possible by other x-ray scattering techniques. This novel method for the determination of the copper layer thickness in spin valves shows the versatility of non-destructive x-ray methods for the characterisation of magnetic metallic multilayers.
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Souza, Geovane Grossi Araújo de. "X-Ray fluorescence imaging system based on Thick-GEM detectors." Universidade de São Paulo, 2019. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21032019-233121/.
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GEMs (Gas Electron Multiplier) and Thick-GEMs (Thick-Gas Electron Multiplier) are MPGDs (Micropattern Gas Detector) that make part of the new generation of gaseous detectors, allowing high counting rates, low cost when compared to solid state detectors, high radiation hardness and gain when using multiple structures. Besides that, the handling and maintenance of these detectors is relatively simple, being versatile to detect different types of radiation. Therefore, these detectors are an effective alternative to build imaging systems with large sensitive area. This work consists in the study and characterization of a set of gaseous detectors, more specifically the Thick-GEMs produced in the High Energy Physics and Instrumentation Center at IFUSP, which were tested showing promising results in terms of gain, energy resolution and operational stability. However, due to the low signal-to-noise ratio of the Thick-GEMs, the X-ray fluorescence imaging system was mounted using GEMs. During this work the necessary software tools for image processing and reconstruction were developed as a parallel study in computational simulations to better understand the operation of gaseous detectors. X-ray fluorescence techniques are essential in areas such as medicine and the study of historical and cultural heritage since they are non-invasive and non-destructive. Techniques to check the authenticity of masterpieces are required and museums are gradually becoming more interested in the Physics and instrumentation needed to characterize their patrimony.Os GEMs (Gas Electron Multiplier) e Thick-GEMs (Thick-Gas Electron Multiplier) são estruturas do tipo MPGD (Micropattern Gas Detector) que fazem parte da nova geração de detectores de radiação a gás e permitem altas taxas de contagens, baixo custo quando comparados com os detectores de estado sólido, uma elevada resistência à radiação e ganhos elevados, quando utilizadas estruturas múltiplas para multiplicação. Além disso, o manuseio e manutenção desses detectores é relativamente simples, sendo versáteis em relação à montagem podendo detectar diferentes tipos de radiação. Sendo assim, a utilização desses detectores é uma alternativa eficiente para montar um sistema de imagem com grande área sensível. Este trabalho consiste no estudo e caracterização de um conjunto de detectores gasosos, mais especificamente os Thick-GEMs produzidos pelo grupo de Física de altas energias e Instrumentação do IFUSP, que foram testados para serem empregados em um sistema de imagem de fluorescência de raios-X. Os Thick-GEMs testados apresentaram resultados promissores em termos de ganho, resolução em energia e estabilidade operacional. No entanto, devido à baixa relação sinal-ruído, um sistema de imagem de fluorescência de raios-X foi montado utilizando GEMs. Durante o trabalho as ferramentas de software necessárias para processamento e reconstrução de imagens foram desenvolvidas, assim como um estudo paralelo de simulações computacionais para entender melhor o funcionamento de detectores gasosos. Técnicas como o imageamento por fluorescência de raios-X são de suma importância pois são consideradas não invasivas e não destrutivas. Sua utilização tem uma importância imprescindível nas áreas da medicina e na análise de patrimônios histórico e cultural. Atualmente, a verificação e validação de autenticidade de obras é um requisito obrigatório e alguns museus começam a se interessar cada vez mais em áreas da Física e da instrumentação necessária para caracterizar o seu patrimônio.
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Murphy, Caitlin Anne. "An analysis of a continuum X-ray Diffraction/Fluorescence instrument." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/114332.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2007.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 40-41).
Scientists at NASA's Goddard Space Flight Center have developed a Combined X-ray Diffraction/Fluorescence (CXRDF) instrument. CXRDF performs simultaneous chemical and structural analysis of an unprepared sample, making it ideal for planetary mineral identification. In an effort to analyze the effectiveness of CXRDF, samples were chosen from a list of minerals that are important in the debate about the origin of the outcrops at Meridiani Planum on Mars. These samples were run on both CXRDF and a laboratory X-ray diffractometer. The datasets were compared, looking at peak identification, d-spacing resolution, and whether the instruments could definitively identify each sample. CXRDF successfully measured the d-spacings for each mineral, and the chemical analysis data were very valuable. However, for CXRDF to be able to definitively identify minerals, its d-spacing range and resolution will need to be improved, in addition to its data analysis software.
by Caitlin A. Murphy.
S.B.
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Shakeshaft, John Thomas. "X-ray fluorescence for the determination of gold in vivo." Thesis, University of Bath, 1992. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306569.
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Geraki, Kalotina. "Differentiating normal and diseased breast tissue using X-ray fluorescence and energy dispersive X-ray diffraction." Thesis, City University London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274458.
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Maraha, Ninwe. "Physiological status of bacteria used for environmental applications /." Stockholm, 2007. http://diss.kib.ki.se/2007/91-7357-063-X/.
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Guedes, Alexis Dourado [UNIFESP]. "Determinação do fenótipo sexual em uma criança com Mosaicismo 45,X/46,X,Idic(Yp): importância da proporção relativa da linhagem 45,X no tecido gonadal." Universidade Federal de São Paulo (UNIFESP), 2006. http://repositorio.unifesp.br/handle/11600/9326.
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Previous issue date: 2006-12-31We report here on a girl who, despite her 45,X/46,X,der(Y) karyotype, showed no signs of virilization or physical signs of the Ullrich-Turner syndrome [UTS], except for a reduced growth rate. After prophylactic gonadectomy due to the risk of developing gonadoblastoma, the gonads and peripheral blood samples were analyzed by fluorescence in situ hybridization [FISH] and polymerase chain reaction [PCR] to detect Y-specific sequences. These analyses allowed us to characterize the Yderived chromosome as being an isodicentric Yp chromosome [idic(Yp)] and showed a pronounced difference in the distribution of the 45,X/46,X,idic(Yp) mosaicism between the two analyzed tissues. It was shown that, although in peripheral blood almost all cells (97.5%) belonged to the idic(Yp) line with a duplicated SRY gene, this did not determine any degree of male sexual differentiation in the patient, as in the gonads the predominant cell line was 45,X (60%).
TEDE
BV UNIFESP: Teses e dissertações
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Sakamoto, Silmara Sanae [UNESP]. "Identificação de elementos traço em tumores de mama de cadelas e sua correlação com histopatologia e prognóstico de vida." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/94699.
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sakamoto_ss_me_araca.pdf: 2232778 bytes, checksum: 2d567023e0bd2b444f0d70e7197d8eaf (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O papel dos elementos traço em tumores mamários tem sido investigado nas últimas décadas, mas comparações de subclasses de tumores mamários malignos são ainda inéditas em medicina veterinária. Portanto, o objetivo do presente trabalho foi identificar a concentração dos elementos cálcio, ferro, cobre e zinco em neoplasias mamárias de cadelas, comparando-se um grupo controle com três tipos histológicos malignos. Cinquenta e uma biopsias mamárias foram avaliadas e divididas em quatro grupos (G1 - controle, G2 - carcinoma complexo, G3 - carcinoma tubular/tubulopapilífero e G4 – carcinoma sólido). O material foi colhido de mastectomias realizadas na rotina do Hospital Veterinário da UNESP-Araçatuba sendo classificado segundo os critérios diagnósticos propostos pela Organização Mundial de Saúde. As amostras foram analisadas, quanto aos elementos traço, pela técnica de Fluorescência de Raios X por Dispersão de Energia (EDXRF). A análise estatística revelou aumento significativo (p<0,05) dos elementos cálcio, ferro e zinco entre os grupos G1 e G2. Comparações entre o sistema TNM (Tumor/Linfonodo/Metástases) e os elementos traço não foram significativas (p˃0,05) à análise estatística, já que os mesmos demonstraram estar correlacionados ao tipo histológico e não ao sistema TNM de prognóstico de vida. O aparelho de EDXRF mostrou-se eficaz para a análise dos elementos traço, além de ser uma técnica mais acessível, multielementar e não destrutiva, permitindo que outras metodologias possam ser utilizadas para estudos complementares com as mesmas amostras
The role of trace elements in breast cancer has been investigated in recent decades, but comparisons of subclasses of malignant mammary tumors are still unpublished in veterinary medicine. So, the aim of this work was to identify the concentration of calcium, iron, cooper and zinc in canine mammary tumors, comparing them with a control group and three malignant neoplasias. 51 mammary fragments of biopsies were analyzed and divided in four groups (G1 – Control, G2 - Complex Carcinomas, G3 – Tubular/Tubulopapillary Carcinoma and G4 – Solid Carcinoma). Samples of the tumors were collected during surgical procedures, mastectomy, performed at Veterinary Hospital of Sao Paulo State University – Araçatuba and were classified according to the diagnostic criteria proposed by the World Health Organization. Samples were analyzed by Energy Dispersive X-Ray Fluorescence Equipment (EDXRF). Statistical analysis revealed a significant difference (p<0.05) only in the groups G1 and G2, concerning to the calcium, iron and zinc elements. The comparison between TNM system and trace elements revealed an absence of statistical evaluation, because trace elements were connected with histopathologycal graduation. The EDXRF was useful for trace element analyses and it is a non-destructive, multielementar technology that permits complementary studies with the same samples
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Sakamoto, Silmara Sanae. "Identificação de elementos traço em tumores de mama de cadelas e sua correlação com histopatologia e prognóstico de vida /." Araçatuba : [s.n.], 2011. http://hdl.handle.net/11449/94699.
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Resumo: O papel dos elementos traço em tumores mamários tem sido investigado nas últimas décadas, mas comparações de subclasses de tumores mamários malignos são ainda inéditas em medicina veterinária. Portanto, o objetivo do presente trabalho foi identificar a concentração dos elementos cálcio, ferro, cobre e zinco em neoplasias mamárias de cadelas, comparando-se um grupo controle com três tipos histológicos malignos. Cinquenta e uma biopsias mamárias foram avaliadas e divididas em quatro grupos (G1 - controle, G2 - carcinoma complexo, G3 - carcinoma tubular/tubulopapilífero e G4 - carcinoma sólido). O material foi colhido de mastectomias realizadas na rotina do Hospital Veterinário da UNESP-Araçatuba sendo classificado segundo os critérios diagnósticos propostos pela Organização Mundial de Saúde. As amostras foram analisadas, quanto aos elementos traço, pela técnica de Fluorescência de Raios X por Dispersão de Energia (EDXRF). A análise estatística revelou aumento significativo (p<0,05) dos elementos cálcio, ferro e zinco entre os grupos G1 e G2. Comparações entre o sistema TNM (Tumor/Linfonodo/Metástases) e os elementos traço não foram significativas (p˃0,05) à análise estatística, já que os mesmos demonstraram estar correlacionados ao tipo histológico e não ao sistema TNM de prognóstico de vida. O aparelho de EDXRF mostrou-se eficaz para a análise dos elementos traço, além de ser uma técnica mais acessível, multielementar e não destrutiva, permitindo que outras metodologias possam ser utilizadas para estudos complementares com as mesmas amostrasAbstract: The role of trace elements in breast cancer has been investigated in recent decades, but comparisons of subclasses of malignant mammary tumors are still unpublished in veterinary medicine. So, the aim of this work was to identify the concentration of calcium, iron, cooper and zinc in canine mammary tumors, comparing them with a control group and three malignant neoplasias. 51 mammary fragments of biopsies were analyzed and divided in four groups (G1 - Control, G2 - Complex Carcinomas, G3 - Tubular/Tubulopapillary Carcinoma and G4 - Solid Carcinoma). Samples of the tumors were collected during surgical procedures, mastectomy, performed at Veterinary Hospital of Sao Paulo State University - Araçatuba and were classified according to the diagnostic criteria proposed by the World Health Organization. Samples were analyzed by Energy Dispersive X-Ray Fluorescence Equipment (EDXRF). Statistical analysis revealed a significant difference (p<0.05) only in the groups G1 and G2, concerning to the calcium, iron and zinc elements. The comparison between TNM system and trace elements revealed an absence of statistical evaluation, because trace elements were connected with histopathologycal graduation. The EDXRF was useful for trace element analyses and it is a non-destructive, multielementar technology that permits complementary studies with the same samples
Orientador: Alexandre Lima de Andrade
Coorientador: Maria Cecília Rui Luvizotto
Coorientador: Andrea Antunes Pereira
Banca: Flávia de Rezende Eugênio
Banca: Paula Rahal
Mestre
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Staufer, Theresa Maria [Verfasser], and Florian [Akademischer Betreuer] Grüner. "X-Ray Fluorescence Imaging with a Laser-Driven X-Ray Source / Theresa Maria Staufer ; Betreuer: Florian Grüner." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/1217408878/34.
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Almalki, Musaed Alie Othman. "Gadolinium Concentration Analysis in a Brain Phantom by X-Ray Fluorescence." Thesis, University of Canterbury. Department of Physics and Astronomy, 2009. http://hdl.handle.net/10092/2864.
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The study was conducted to develop a technique that measures the amount of gadolinium based contrast agent accumulated in a head tumour by x-ray fluorescence, while a patient is exposed to neutrons or during external beam radiotherapy planning. In this research, measurements of the gadolinium concentration in a vessel simulating a brain tumour located inside a head phantom, by the x-ray fluorescence method were taken, where the Magnevist contrast medium which has gadolinium atom, in the tumour vessel, was excited by a 36 GBq (0.97 Ci) 241Am source that emits gamma rays of 59.54 keV, in 35.7 % of it’s decays, resulting the emission of characteristic fluorescence of gadolinium at 42.98 keV that appeared in the X-ray fluorescence spectrum. A Cadmium Telluride (CdTe) detector was used to evaluate and make an analysis of the gadolinium concentration. Determinations of the gadolinium content were obtained directly from the detector measurements of XRF from gadolinium in the exposed tumour vessel. The intensity measured by the detector was proportional to the gadolinium concentration in the tumour vessel. These concentrations of gadolinium were evaluated for dose assessment. The positioning of the head phantom was selected to be in the lateral and vertex positions for different sizes of tumour vessels. Spherical tumour vessels of 1.0, 2.0, 3.0 cm and an oval tumour vessel of 2.0 cm diameter and 4.0 cm length, containing the gadolinium agent, contained concentration between 5.62 to 78.63 mg/ml. They were placed at different depths inside a head phantom at different positions in front of the detector and the source for the measurements. These depths ranged from 0.5 cm to 5.5 cm between the center of the tumour and interior wall of the head phantom surface. The total number of measurements in all four sizes of the tumour vessel was 478; 78 examinations of a 1.0 cm spherical tumour vessel, 110 examinations of a 2.0 cm spherical tumour vessel, 150 examinations of a 3.0 cm spherical tumour vessel and 140 examinations of a 2.0 x 4.0 cm ellipsoid tumour vessel. To measure the size and the shape of the tumour by the alternative radiographic method, a general x-ray machine with radiograph film was used. Based on that, the appropriate shape of concentration could be selected for therapy. The differences of optical density in the x-ray films showed that the noise was increased with low concentration of the Gd. Because radiographic film may be subjected to different chemical processes where the darkness will be affected, these measurements would be very hard to be quantitative. Accordingly it is difficult to use the film for Gd concentrations. The obtained data show that the method works very well for such measurements.
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O'Meara, Joanne M. "Measuring lead, mercury, and uranium by in vivo x-ray fluorescence." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0033/NQ66229.pdf.
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Al-Sadhan, F. A. O. "An evaluation of alternative sources for in vivo X-ray fluorescence." Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635712.
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This thesis describes the application of X-ray fluorescence to the detection of heavy metals in the body. Platinum is a heavy metal of importance in medicine, particularly in oncology, in the form of anti-cancer drugs. These are used against several human tumours including neck and head, ovarian cervical and testicular cancer. Even though successfully and widely used, platinum has undesirable toxic side effects including nephrotoxocity, nausea, vomiting and neurotoxicity. Information about the concentration of the drug in the tumour could be of use in establishing dose-response relationships and in adjusting a patient's subsequent doses of the drug to achieve maximum therapeutic effect. A system for the in vivo measurement of platinum in patients treated with chemotherapy has been developed, based on a Tc-99m annular source in back-scattering geometry. The collimator to skin distance was determined for optimum dosimetry and detection limit, and the effect of overlying tissue and tumour volume measured. The dosimetry, detection limit, performance, availability and cost were compared with those of a system based on a Co-57 'point' source in 90°-scattering geometry. The amount of adsorbed dose to the patient was predicted using a mathematical model (Target) and the results showed good agreement with both a newly-written BASIC program and values measured using thermoluminescence dosimetry. Two computer programs were tested and used for the analysis of the spectra obtained from the patients. Fifteen measurements of platinum in head and neck tumours were performed in seven patients. The results showed that the new system has several advantages compared with the previous one.
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COHEN, VICTOR H. "Determinacao simultanea de actinideos por spectrometria de fluorescencia de raios-X." reponame:Repositório Institucional do IPEN, 1990. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10248.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Lawrence, Edward R. (Edward Robert) Carleton University Dissertation Physics. "The variables controlling the intensity and purity of fluorescence X Rays." Ottawa, 1993.
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SCAPIN, MARCOS A. "Aplicacao da difracao e fluorescencia de raios X (WDXRF): ensaios em argilominerais." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11251.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Koirala, Amod K. "Use of fluorescence excitation emission matrix spectroscopy for water and wastewater." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/5875.
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Thesis (M.S.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 14, 2007) Vita. Includes bibliographical references.
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HADJ-BOUSSAAD, DJAMAL EDDINE. "Determination des teneurs elementaires dans les minerais par fluorescence x a dispersion d'energie (e. D. X. R. F)." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13136.
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Mise en evidence des avantages et des limites de la fluorescence x a dispersion d'energie pour l'analyse elementaire dans les solides (roches et minerais riches en uranium, molybdene et thorium). L'optimisation des parametres composant le spectrometre a excitation directe (puissance, intensite, tension, temps d'irradiation et surtout le choix du filtre, notamment l'etain pour eliminer le fond continu) permet la detection simultanee dans un domaine d'energie tres etendu ce qui accroit le nombre d'elements determinables
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Santos, Shirley Pereira. "Analise de materiais em suspensão de aguas por espectrometria de fluorescencia de raios X : avaliação de metodo." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/286797.
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Orientador: Jacinta EnzweilerDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: Tipicamente, análises de águas em sistemas naturais são realizadas após a filtração por membrana com diâmetro de poro de 0,45 J..lm. O material particulado em suspensão retido durante a filtração, que na maior parte dos casos é descartado sem ser analisado, é de grande interesse, pois, permite avaliar diversos parâmetros de meios aquáticos. Dentre eles, os mais importantes são a quantidade e a composição de material transportado. Uma característica do material particulado em suspensão é sua grande capacidade de retenção de espécies químicas e, por isto, o destino maior parte dos metais presentes em sistemas aquáticos está associado com o destes sedimentos. Neste trabalho desenvolveu-se um método para analisar diretamente o material particulado depositado nos filtros, utilizando-se a espectrometria de tluorescência de raios X com dispersão de comprimento de onda, e correção de efeitos matriz baseados em parâmetros fundamentais. Uma calibração dedicada foi preparada, empregando como padrões materiais de referência certificados de sedimentos e solos, depositados em filtros. Da mesma forma, avaliou-se a exatidão dos resultados, os quais demonstraram ser possível a determinação quantitativa de elementos maiores e a semi-quantitativa de elementos-traço nos materiais estudados, indicando que o método proposto é adequado quando se deseja monitorar e estudar ambientes aquáticos, pois é simples e rápido. Amostras de material particulado em suspensão de água coletada em dois rios foram analisadas. Os resultados finais dependem da composição global da amostra, isto é, do tipo e concentração dos elementos (p.ex., C, H, N) presentes no material particulado e não dosados na FRX. Se conhecidos, estes componentes podem ser informados durante os cálculos. O método também pode ser adaptado para analisar pequenas quantidades de materiais pulverizados, insolúveis em água
Abstract: Typically, analyses of waters in natural systems are carried out after filtration on membranes with diameter of pore of 0.45 pIIl. The suspended particuJate material retained during the filtration, wbich is discarded without analysis in most cases, is of great interest because it can be used to evaluate important parameters of aquatic media. lhe most important are the quantity and ~on of transported sediments. A characteristic of suspended particu1ate material is its great capacity of retention of chemical species and for tbis reason these sedimeots control the fàte of metais in aquatic systems. In tbis work, a metbod was developed to analyze the suspeoded particu1ate material deposited on fiIters, directly by wavelength X-ray tluorescence spectrometry (WD XRF). Matrix correctioos
Mestrado
Metalogenese
Mestre em Geociências
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Chu, Manh-Hung. "Structural and chemical characterization of single Co-implanted ZnO nanowires by a hard X-ray nanoprobe." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY016/document.
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Ce travail de thèse porte sur l'analyse de nanofils de ZnO dopés au cobalt par implantation ionique, en utilisant la fluorescence des rayons X, la spectroscopie d'absorption des rayons X et les techniques de diffraction des rayons X à l'échelle nanométrique sur la ligne de lumière ID22 de l'Installation Européenne de Rayonnement Synchrotron. Les nanofils sont obtenus par croissance catalysée sur des substrats de p-Si (100). Les nanofils de ZnO synthétisés ont été dopés avec du cobalt par d'implantation ionique. Pour la première fois, l'utilisation combinée des techniques de caractérisation par rayons X citées ci-dessus nous permet d'étudier l'homogénéité de la distribution des dopants, la composition, ainsi que l'ordre structurel à courte et grande distance de nanofils individuels. Les résultats de la nano-fluorescence des rayons X indiquent que le dopage au cobalt par implantation ionique dans les nanofils de ZnO est homogène, avec les concentrations désirées. La spectroscopie d'absorption de rayons X et l'analyse des données de diffraction de rayons X fournissent de nouvelles informations sur la distorsion du réseau cristallin produite par l'introduction de défauts structuraux par le processus d'implantation ionique. Ces résultats soulignent l'importance du recuit thermique après l'implantation pour récupérer la structure des nanofils de ZnO à l'échelle du nanomètre. Les mesures complémentaires de micro-photoluminescence et cathodo-luminescence corroborent ces résultats. En conclusion, les méthodes utilisées dans cette thèse ouvrent de nouvelles voies pour l'application de mesures multi-techniques basées sur le rayonnement synchrotron pour l'étude détaillée des nanofils semi-conducteurs à l'échelle nanométriqueThe PhD dissertation focuses on the investigation of single Co-implanted ZnO nanowires using X-ray fluorescence, X-ray absorption spectroscopy, and X-ray diffraction techniques with nanometer resolution at the beamline ID22 of the European Synchrotron Radiation Facility. The ZnO nanowires were grown on p-Si (100) substrates using vapor-liquid-solid mechanism. The synthesized ZnO nanowires were doped with Co via an ion implantation process. For the first time, the combined use of these techniques allows us to study the dopant homogeneity, composition, short- and large-range structural order of individual nanowires. The nano-X-ray fluorescence results indicate the successful and homogeneous Co doping with the desired concentrations in the ZnO nanowires by an ion implantation process. The nano-X-ray absorption spectroscopy and X-ray diffraction data analyses provide new insights into the lattice distortions produced by the structural defect formation generated by the ion implantation process. These findings highlight the importance of the post-implantation thermal annealing to recover the structure of single ZnO nanowires at the nanometer length scale. Complementary microphotoluminescence and cathodoluminescence measurements corroborrate these results. In general, the methodologies used in this work open new avenues for the application of synchrotron based multi-techniques for detailed study of single semiconductor nanowires at the nanoscale
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Zimina, Anna. "Novel nanomaterials studied by the method of soft X-ray fluorescence spectroscopy." [S.l.] : [s.n.], 2006. http://opus.kobv.de/tuberlin/volltexte/2007/1426.
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Gajdosik, Vincent. "Phase-contrast and fluorescence X-ray imaging of soft and bio matter /." [S.l.] : [s.n.], 2009. http://library.epfl.ch/theses/?nr=4487.
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Shwartz, Pamela. "X-ray fluorescence analysis of ceramics from Santa Rita B, Northern Peru." Tallahassee, Florida : Florida State University, 2010. http://etd.lib.fsu.edu/theses/available/etd-04122010-172632/.
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Thesis (M.S.)--Florida State University, 2010.Title and description from dissertation home page (viewed on July 28, 2010). Advisors: Cheryl Ward and Glen Doran, Florida State University, College of Arts and Sciences, Dept. of Anthropology. Includes bibliographical references.
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Wilemon, Billy B. Jr. "Portable X-Ray Fluorescence Spectrometer Analysis of the Pylos Linear B Tablets." Thesis, Mississippi State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10642684.
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This thesis investigates similarities in the chemistry of the Linear B clay tablets and sealings found at the Palace of Nestor in Pylos, located in the western Peloponnese. These similarities, or lack thereof, provide clues to the flow of material goods in and out of the palace and therefore to the degree of centralization of the government. Over a thousand 3000 year-old clay tablets and sealings currently housed at the National Archaeological Museum in Athens were analyzed using a pXRF over the course of the summers of 2015 and 2016. The chemical compositions were analyzed statistically. Results of the study and the conclusions are presented here.
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Saraci, Mirela P. "Errors in analysis of sulphide rich samples by x-ray fluorescence spectrometry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63060.pdf.
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Luck, Sara Rosalind. "X-ray fluorescence spectroscopy at long wavelengths : elemental and chemical state analysis." Thesis, Queen Mary, University of London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264922.
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Magem, Blanca Rodríguez. "Study of metal objects of Lombardian origin using X-Ray Fluorescence analysis." Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/31459.
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Introduction: 1.1.- Preface and aims -
The Museo dell’Alto Medioevo of Rome opened its gates in 1967 as part of the complex of the Museo de la Cività, becoming since then home to remarkable pieces from the central part of Italy, from the time period comprised between the fall of the Western Roman Empire in 476 AD and around 1000 AD. Its main collection comprises an impressive amount of metal pieces, ceramics and stone decorations from late antiquity Rome to Carolingian era, and even a treasure from the Copts. The most impressive of all these treasures might be the Room of the opus sectile of Porta Marina from Ostia, made with coloured marble pieces embedded into the floor and the walls, creating geometric, vegetal and animal decorative motifs. Amongst all the objects of the collection, those from the necropolis of Nocera Umbra and Castel Trosino are specially relevant because of their high artistic value, many of them made in precious metals like gold and silver. These two are some of the largest early medieval necropolises in central Italy from Lombardian origin. Lombardian domination in Italy begins in the VI Century, around the year 568 AD, and ends in the year 774 AD with the fall of the Lombardian Kingdom by the hand of the Franks, led by Charlemagne. Ever since their discovery at the start of the 20th century, there have been many studies about these objects and the necropolises themselves, specially from to ‘90s up to today.
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Heimburger, Robert. "Determination d'elements traces dans les poudres par fluorescence x a dispersion d'energie." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13052.
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